There is now large-scale epidemiological evidence that aspects of chronic psychological stress, such as early adversity or job strain, and early life stress, predict earlier disease onset and mortality. Despite documentation of the importance of stress to health, there are several critical barriers that prevent progress in the epidemiological study of stress as a risk factor for disease. Measurement of stress is inherently complex and multi-level (e.g., social, psychological, physiological). There are few agreed upon 'gold standard' measures of stress, hence measurement is often inconsistent and superficial where heterogeneous constructs are conflated. There is also little understanding of the conditions under which stress exposure can promote vulnerability vs. resiliency to disease. Meanwhile, there have been rapid advances in the basic science of stress processes, which have helped to unpack the cognitive and affective components, links to brain and peripheral physiological responses, and richer measures of daily stress - e.g., through ecological momentary assessments using technology to obtain detailed profiles of exposures and contexts. Thus, epidemiological stress science can benefit from a more coherent multilevel model that encompasses better measurement of lifespan exposures and responses, including the social, psychological, and physiological indices of stress that have the greatest impact on health. The proposed R24 will recruit excellent scientists with relevant methods to apply their interests to th advancement of stress measurement across human development, with a focus on how lifespan stress affects health in mid to late life. Aims include: 1) Development of a stress measurement taxonomy, including guidelines for best measurement; 2) Development of a 'toolbox' of short measures of stress that can be used in epidemiological studies of adult aging internationally. These will be drawn from innovative measurement from basic experimental and field research, refinement/shortening of existing measures, and results from comparative validation of promising measures; and 3) Promotion of stress research in epidemiological studies of aging, both through harmonizing existing measures and adding new toolbox measures. This in turn will lead to discoveries that refine the taxonomy and research methodologies. Improved stress measurement offers tremendous opportunities for advancing the field of basic research, enhancing the efficacy of health-promotion interventions and policy.